I managed to upgrade my aging Synology DS218+ to 16GB of RAM (although it officially only supports 6GB).

There's a handy crowd-sourced spreadsheet of compatible RAM for Synologies to breathe more life into them:

https://docs.google.com/spreadsheets/d/13pJDfDot_7CmSWeo1jjbegM82QwQNIW0gFQ9o_4xhXA/edit?gid=1974572930#gid=1974572930

Synology RAM Compatibility List (Responses)

Google Docs
@jernej
The real question is where did you find all that money needed to buy that much RAM 😁

@grote haha, I'm lucky that it still uses DDR3 so it was like 40€

Poor people with DDR4 tho.